A rapid and sensitive method for characterization and quantification of polyglycerol esters by supercritical fluid...

Polyglycerol esters of fatty acids (PGEs), a very complex mixture of various isomers, are widely used as green surfactants in different industrial fields such as in cosmetic, pharmaceutic and food industries. However, no study related to the purification and the absolute quantification of these compounds has been described yet. In this study, we developed a rapid and efficient method for characterization and quantification of PGEs using Supercritical Fluid CO₂ coupled to High-Resolution Mass Spectrometry (SFC-HRMS). The SFC conditions were first considered including the stationary phase, the nature of mobile phase, the column temperature, the back-pressure regulator. The MS parameters (drying-gas temperature, capillary voltage, nozzle voltage, fragmentor voltage) were then investigated to get the best sensitivity for the PGE analysis. The MS/MS-based structural characterization of targeted PGE, triglycerol mono-oleate (PG3+1C18:1), was established and is helpful to study complex mixtures of PGEs with numerous isobaric PGEs. PG3+1C18:1 was then purified at lab scale and used as standard for quantification. This enabled to develop a rapid quantification method for PG3+1C18:1 within 12 min with good linearity (R² = 0.9997) as well as sensitivity (picogram level). The validated method was then successfully applied to quantify PG3+1C18:1 in commercial products in order to evaluate their composition.